Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/64—Polyesters containing both carboxylic ester groups and carbonate groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G64/00—Macromolecular compounds obtained by reactions forming a carbonic ester link in the main chain of the macromolecule
  • C08G64/04—Aromatic polycarbonates
  • C08G64/06—Aromatic polycarbonates not containing aliphatic unsaturation
  • C08G64/14—Aromatic polycarbonates not containing aliphatic unsaturation containing a chain-terminating or -crosslinking agent
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G64/00—Macromolecular compounds obtained by reactions forming a carbonic ester link in the main chain of the macromolecule
  • C08G64/20—General preparatory processes
  • C08G64/30—General preparatory processes using carbonates

Definitions

• the invention concerns a transesterification process for modifying a polymeric resin, more particularly the process concerns a transesterification reaction in the melt between a cyclic carbonate and a polycarbonate or a polyester resin.
• a process whereby a polymeric resin (containing ester and/or carbonate bonds) is readily converted into a resin having a modified molecular structure.
• a cyclic carbonate (a monomer or oligomer) is transesterified with the polymer resin in the melt, preferably upon extrusion, optionally in the presence of a catalyst.
• the cyclic carbonate which may include any of a variety of functional groups may, by the inventive process, be inserted into the structure of the polymer, effecting a modification to the structure and the properties of the resin.
• beneficial modifications thus imparted to the resin are improved thermal stability, altered rheology and optical properties.
• polyesters and polyestercarbonate resins and methods for their manufacture are known. Transesterification as a method for making polyesters and polycarbonates is also well known. See in this regard Chemistry and Physics of Polycarbonate, by Hermann Schnell Interscience Publishers, John Wiley & Sons, Inc., 1964, pp. 44-51 and in Polycarbonate by William F. Christopher and Daniel W. Fox; Reihhold Publishing Corporation, New York, 1962, pp.13-15.
• transesterification refers to an intermolecular reaction between chains.
• transesterification refers to interchanges between a cyclic carbonate and a carbonate and/or ester bond.
• Stabilizers are commonly incorporated into polycarbonates, polyesters and polyestercarbonates by physical mixing. Due in part to their relatively small size, concerns with such stabilizers include their toxicity, volatility, blooming, rate of diffusion, leaching, plasticization and distribution within the matrix. Some of these problems have been investigated. In the area of polymeric antioxidants, for example, note may be made of an article by Coleman et al. in Macromolecules 1994, 27, 127 and of the references mentioned therein.
• the preparation and reported utilization of low molecular weight, low viscosity cyclic precursors that may be ring-opened to form high molecular weight polymers have been reported by Brunelle et al. in Indian Journal of Technology Vol 31, April-June 1993, pp 234-246 and in J. Amer. Chem. Soc., 1990, 112, 2399. Ring-opening polymerization of such cyclics is reported to lead to complete conversion to high molecular weight linear polymers.
• the art also includes U.S. patent 5,281,669 which disclosed easily flowable blends containing linear polymers and oligomers having an overall cyclic structure, and U.S. patent 4,605,731 which disclosed a method for preparing polycarbonate resins from cyclic polycarbonate oligomers, the reaction being catalyzed by a particular borate compound.
• the present invention is predicated on the finding that cyclocarbonates, optionally containing a radical, moiety or group the inclusion of which in the structure of the resin effects a change in the properties of the resin (herein Group), may advantageously be inserted, by transesterification reaction, in the melt, into the structure of polycarbonates, polyesters or polyestercarbonate resins.
• the reaction results in a structurally modified resin, featuring changed properties.
• the resulting properties of the resin are determined by the efficiency of the process and by the identity and relative amount of the cyclocarbonate and/or Group thus inserted.
• transesterification refers to an intermolecular reaction between chains; more particularly to interchanges between a cyclic carbonate and a polycarbonate, preferably a linear polycarbonate.
• a polycarbonate resin is transesterified in the melt, for instance in an extruder, optionally in the presence of a suitable transesterification catalyst, with a cyclic carbonate oligomer, the process results in a modified polycarbonate.
• the process of the invention may be represented by and as follows: and by
• Cyclic carbonates which are suitable in the presently disclosed invention may be synthesized by an interfacial process in either of the following three ways: (A) a bisphenol may first be made into its corresponding bischloroformate which is then cyclized, the result is that a bisphenol is present in each repeat unit, (B) different bischlorofomate compositions can be ratioed to achieve the desired composition, and (C) a desired moiety may be reacted in its bisphenolic form (up to 20 mole %) with bisphenol A bischloroformate. These are represented schematically as where X and R independently denote residues, and n and m are the respective degrees of cyclization.
• reaction refers to the structure of a bischloroformate without its carbonyl groups or its chlorine atoms, and to the structure of a dihydroxy compound without the hydroxy groups.
• Monocyclic carbonates which are suitable in the process of the present invention are known and their preparation is conventional.
• An example of a suitable monocyclic is 1,3-dioxolan-2-one (ethylene carbonate).
• the present invention relates to a transesterification process, reacting a polycarbonate resin with at least one cyclic carbonate, optionally in the presence of a suitable catalyst, carried out in the melt, preferably in an extruder or in other apparatus enabling melt processing of the reactants, preferably at temperatures in the range of 250 to 350°C and at a residence time sufficient to enable the transesterification reaction, preferably up to about 5 minutes, resulting in the insertion of said carbonate in the resin.
• the cyclic carbonate optionally contains a Group, as previously defined. The resulting properties of the resin are determined by the efficiency of the process and by the identity and relative amount of the cyclocarbonate and/or Group thus inserted.
• the terms "functionalized cyclic carbonate” refers to cyclic carbonates the structure of which includes Group(s).
• any one, or combination of functionalized cyclic carbonates may be thus inserted resulting in a modified resin, the modification in this instance amounting to conferring the function of Group included in the functionalized cyclic carbonate onto the resin.
• the functionalized cyclic carbonate may include Groups the functions of which impart to the resin improved mechanical and/or physical properties, mold release properties, optical properties, such as UV stability or antioxidation characteristics, to name but a few. Examples of suitable group include triphenylphosphine, benzophenone and BHT which groups impart stability to the resin, radicals which contain phosphorus and/or sulphur atoms which impart flame retardance to the resin and groups effecting the compatibility of the resin in blends with other resins.
• One or more of these functionalized cyclic carbonates may be inserted, optionally simultaneously, in accordance with the invention to modify a conventional, commercially available resins.
• cyclic oligocarbonates entails a triethylamine-catalyzed hydrolysis/condensation reaction of bischloroformate.
• the cyclic carbonate suitable in the present invention is a member selected form the group consisting of and wherein X and R independently denote an aliphatic, cycloaliphatic or an aromatic residue of a dihydroxy compound or of a bischloroformate, and where R may optionally contain a Group, Y denotes a trifunctional or fetrafunctional nucleophile, n, n 1 ,n 2 and n 3 independently denote an integer of 0 to 16. It is specifically understood that, in view of the disclosure in U.S.
• An illustrative example of the process of the invention is the insertion, in a polycarbonate resin, of a functional cyclic oligocarbonate wherein Group conform to
• the thus modified polycarbonate exhibits UV-filtering properties.
• the optional catalyst useful in the process of the present invention is selected from the group consisting of dibutyltin oxide, cobalt (II) acetate tetrahydrate, antimony (III) oxide, manganese (II) acetate tetrahydrate, titanium (IV) butoxide, zinc acetate dihydrate, dibutyltin dilaurate, tin(II) acetate, tetramethyldiacetoxystannoxane, tin (IV) oxide, lead(II) acetate trihydrate, dibutyltin diacetate and titanium (IV) bis(ethylacetoacetate).
• the polycarbonate modified in accordance with the inventive process are homopolycarbonates and copolycarbonates and mixtures thereof.
• the polycarbonates generally have a weight average molecular weight of 10,000-200,000, preferably 20,000-80,000 and their melt flow rate, per ASTM D-1238 at 300°C, is about 1 to about 65 g/10 min., preferably about 2-15 g/10 min.
• They may be prepared, for example, by the known diphasic interface process from a carbonic acid derivative such as phosgene and dihydroxy compounds by polycondensation (see German Offenlegungsschriften 2,063,050; 2,063,052; 1,570,703; 2,211,956: 2,211,957 and 2,248,817; French Patent 1,561,518; and the monograph H. Schnell, "Chemistry and Physics of Polycarbonates", Interscience Publishers, New York, New York, 1964, all incorporated herein by reference).
• Dihydroxy compounds suitable for the preparation of the polycarbonates of the invention conform to the structural formulae (1)
• dihydroxy compounds useful in the practice of the invention are hydroquinone, resorcinol, bis-(hydroxyphenyl)-alkanes, bis-(hydroxyphenyl)-ethers, bis-(hydroxyphenyl)-ketones, bis-(hydroxyphenyl)-sulfoxides, bis-(hydroxyphenyl)-sulfides, bis-(hydroxyphenyl)-sulfones, and ⁇ , ⁇ -bis-(hydroxyphenyl)-disopropyl-benzenes, as well as their nuclear-alkylated compounds.
• aromatic dihydroxy compounds are described, for example, in U.S. patents 3,028,356; 2,999,835; 3,148,172; 2,991,273; 3,271,367; and 2,999,846, all incorporated herein by reference.
• suitable bisphenols are 2,2-bis-(4-hydroxyphenyl)-propane (bisphenol A), 2,4-bis-(4-hydroxyphenyl)-2-methylbutane, 1,1-bis-(4-hydroxyphenyl)-cyclohexane, ⁇ , ⁇ '-bis-(4-hydroxyphenyl)-p-diisopropylbenzene, 2,2-bis-(3-methyl-4-hydroxyphenyl)-propane, 2,2-bis-(3-chloro-4-hydroxyphenyl)-propane, bis-(3,5-dimethyl-4-hydroxyphenyl)-methane, 2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)-propane, bis-(3,5-dimethyl-4-hydroxyphenyl)-sulfide, bis-(3,5-dimethyl-4-hydroxyphenyl)-sulfoxide, bis-(3,5-dimethyl-4-hydroxyphenyl)-sulfone, dihydroxybenz
• aromatic bisphenols examples include 2,2-bis-(4-hydroxyphenyl)-propane, 2,2-bis-(3,5-dimethyl-4-hydroxyphenyl)-propane and 1,1-bis-(4-hydroxyphenyl)-cyclohexane.
• bisphenol A 2,2-bis-(4-hydroxyphenyl)-propane
• the polycarbonate resins suitable as reactants in the process of the invention may entail in their structure units derived from one or more of the suitable bisphenols.
• phenolphthalein-based polycarbonate phenolphthalein-based polycarbonate
• copolycarbonates terpolycarbonates
• terpolycarbonates such as are described in U.S. patents 3,036,036 and 4,210,741, both incorporated by reference herein.
• the polycarbonates suitable as reactants in the process of the invention may also be branched by condensing therein small quantities, e.g., 0.05-2.0 mole % (relative to the bisphenols) of polyhydroxyl compounds.
• polyhydroxyl compounds which may be used for this purpose: phloroglucinol; 4,6-dimethyl-2,4,6-tri-(4-hydroxyphenyl)-heptane; 1,3,5-tri-(4-hydroxphenyl)-benzene; 1,1,1-tri-(4-hydroxyphenyl)-ethane; tri-(4-hydroxyphenyl)-phenylmethane; 2,2-bis-[4,4-(4,4'-dihydroxydiphenyl)]-cyclohexyl-propane; 2,4-bis-(4-hydroxy-1-isopropylidine)-phenol; 2,6-bis-(2'-dihydroxy-5'-methylbenzyl)-4-methylphenol; 2,4-dihydroxy-benzoic acid; 2-(4-hydroxyphenyl)-2-(2,4-dihydroxyphenyl)-propane and 1,4-bis-(4,4'-dihydroxy-triphenylmethyl)-benzene
• Suitable polycarbonate resins are available in commerce, for instance, Makrolon FCR, Makrolon 2600, Makrolon 2800 and Makrolon 3100, all of which are bisphenol based homopolycarbonate resins differing in terms of their respective molecular weights and characterized in that their melt flow indices (MFR) per ASTM D-1238 are about 16.5-24, 13-16, 7.5-13.0 and 3.5-6.5 g/10 min., respectively. These are products of Bayer Corporation of Pittsburgh, Pennsylvania.
• a polycarbonate resin suitable in the practice of the invention is known and its structure and methods of preparation have been disclosed, for example in U.S. patents 3,030,331; 3,169,121; 3,395,119; 3,729,447; 4,255,556; 4,260,731; 4,369,303 and 4,714,746 all of which are incorporated by reference herein.
• the preferred embodiment of the inventive process is carried out using linear polycarbonate resin.
• the (co)polyester suitable in the present invention comprise repeat units from at least one C 6-20 aromatic, C 3-20 aliphatic or alicyclic dicarboxylic acid and repeat units from at least one C 2-20 aliphatic glycol.
• dicarboxylic acids include malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, sebacic, dodecanedioic, 1,4-, 1,5- and 2,6-decahydronaphthalene dicarboxylic acid, and cis- or trans-1,4-cyclohexane dicarboxylic acid.
• aromatic dicarboxylic acid examples include terephthalic acid; isophthalic acid; 4,4'-biphenyldicarboxylic acid; trans 3,3'- and trans 4,4'-stilbenedicarboxylic acid, 4,4'-dibenyldicarboxylic acid; 1,4-, 1,5'-, 2,3'-, 2,6, and 2,7-naphthalenedicarboxylic acid.
• the preferred dicarboxylic acids are terephthalic and isophthalic acid or mixtures thereof.
• the preferred glycol of the (co)polyester includes 2 to 8 carbon atoms.
• Examples include ethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-, 1,3- and 1,4-cyclohexanedimethanol, neopentyl glycol, and 2,2,4,4-tetramethyl-1,3-cyclobutanediol.
• the preferred diols are 1,4-cyclohexanedimethanol, ethylene glycol and mixtures thereof.
• the preferred (co)polyesters include resins having repeat units from poly(ethylene terephthalate) or poly(1,4-cyclohexylenedimethylene terephthalate).
• Preferred (co)polyesters comprise repeat units from terephthalic acid, isophthalic acid or mixtures thereof and 1,4-cyclohexanedimethanol.
• Other preferred (co)polyesters comprise repeat units from terephthalic acid and 1,4-cyclohexanedimethanol, ethylene glycol or mixtures thereof.
• the (co)polyesters of the invention have as a rule inherent viscosity of about 0.4 to 1.0 dl/g, preferably about 0.6 to 0.8 dl/g at 25°C in a solvent containing 60 wt.% phenol and 40 wt.% tetrachloroethane.
• a solvent containing 60 wt.% phenol and 40 wt.% tetrachloroethane a solvent containing 60 wt.% phenol and 40 wt.% tetrachloroethane.
• polyestercarbonates and thermoplastic polyurethanes which contain ester segments.
• the inventive process is preferably carried out in an extruder preferably a twin screw extruder.
• the molecular weights (both the number average and weight average molecular weight) were determined by Gel Permeation Chromatography (GPC).
• samples were analyzed on a Waters 150C high temperature gel permeation chromatography equipped with differential refractive index detector. Tetrahydrofuran served as the mobile phase.
• the conditions for GPC analysis were as follows. Four stainless steel columns (7.8 x 300 mm) were packed with PL Gel SDVB (2 mixed beds + 1x500A + 1x100 ⁇ ) having a mean particle diameter of 10 ⁇ m. The flow rate was 1.0 mL/min. and the injection volume was 75 ⁇ L. A temperature of 35°C was utilized for both GPC and the RI detector. Samples prepared to known concentration ( ⁇ 0.5%) were dissolved in the mobile phase and had toluene added as a flow standard.
• Samples were analyzed on a Perkin Elmer HPLC equipped with the 235C Diode Array Dector, monitoring wavelengths 265 nm and 300 nm. The same conditions for GPC analysis as described above were followed with the following exceptions.
• the samples were prepared to a known concentration of 1% and no flow standard was added.
• the injection volume was 100 ⁇ l and the system was run at ambient temperature. Analysis of chromatograms (overlaying etc.) was performed using ACCESS*CHROM GC/LC software on a VAX based system.
• Makrolon 2408 is a commercial endcapped polycarbonate. This method was used to characterize the phenolic endgroups formed during processing, which can lead to quinone formation, hence color instability in polycarbonate. An integral ratio was determined of the phenoxy endgroup protons (8.3-8.4 ppm) relative to the six isopropylidine bisphenol A aliphatic protons (1.6-1.8 ppm) within the bisphenol A polycarbonate. This integral ratio allows for a qualitative comparison of the phenoxy endgroups formed during processing.
• Cyclic oligocarbonates containing binaphthol (3 g) were dried and added to Makrolon 2608 resin (27 g). The mixture was then processed in a Haake Kneader, without catalyst , under the following conditions: 15 minutes, 200 rpm, nitrogen atmosphere.
• the binaphthol moiety was determined by GPC equipped with a UV-vis detector to be evenly distributed in all molecular weights in the polycarbonate backbone.
• the schematic below represents the process:
• the process of the invention has been demonstrated by carrying the experiment described in Example 2 was carried out except that for the addition of 300 ppm dibutyl tin oxide.
• an increase in the rate of insertion of the cyclic compounds into the polycarbonate backbone was observed.
• the rate of the cyclic insertion reaction was determined by taking aliquots of the melt during processing, and analyzing the extent of cyclic incorporation by GPC-UV/vis.
• the molecular weight as determined by Gel Permeation Chromatography (GPC) was maintained. This is believed to be due to the cyclics having been inserted into the PC backbone by a transesterification mechanism; the binaphthol moiety was determined to be evenly distributed in all molecular weights in the polycarbonate backbone, as determined by GPC equipped with a UV-vis detector.
• GPC Gel Permeation Chromatography
• binaphthol was melt processed with polycarbonate resin in a level of 1 wt. %. As shown in table 1, the molecular weight had decreased as determined by Gel Permeation Chromatography. This is believed due to cleaving of chains by intermolecular alcoholysis. Table 1 Molecular Weight Characterization of Modified Polycarbonates Composition Processing Conditions a Mn b (Std. Dev.) g/mol Mw b (Std. Dev.) g/mol Mw/Mn Makrolon 2408 300°C 15 min.
• the rheology modification was determined by GPC and by measurement of the melt flow rate (MFR).
• MFR melt flow rate
• Table 2 Molecular Weight and Melt Flow Characterization for Rheology Modified Polycarbonate.
• a 1.0 liter Morton flask equipped with a mechanical stirrer and condenser was charged with CH 2 Cl 2 (200 ml), water (7 ml), 9.75 M NaOH (3 ml, 29 mmole), and triethylamine -Et 3 N- (2.4 ml, 17.25 mmole).
• the solution is heated to reflux, vigorously stirred, and a solution of bisphenol A-bischloroformate (200 ml of 1.0 M in CH 2 Cl 2 ) is added subsurface over the tip of the impeller at 6.7 ml/min., using a peristaltic pump. Concurrently, 9.75 M NaOH (59 ml, 575 mmole) was delivered over 25 min.
• the product represents a mixture wherein n ranges up to about 16.
• the cyclic oligocarbonates based on bisphenol A prepared in Example 7 were melt blended with Makrolon 2608 polycarbonate resin in a Haake Kneader under the following conditions: 5 minutes, 300°C, 200 rpm. Transesterification catalysts (300 ppm) were introduced in the melt reaction to determine their relative efficacy in incorporating the cyclic carbonates into the linear polycarbonate by transesterification insertion. Gel Permeation Chromatography (GPC) equipped with a refractive index detector was used to characterize the final resin in terms of molecular weight. The results are presented in Table 3.
• the table shows the molecular weight characterization of polycarbonate resin which has been melt reacted with 10 wt.% cyclic oligocarbonates based on bisphenol A and the dependence of the molecular weight on the catalyst used in the reaction.
• Table 3 Example System Mn (g/mole) Mw (g/mole) Mw/Mn A Makrolon 2608 resin (no cyclics,no catalyst) 10810 29170 2.7 B Makrolon 2608 resin, cyclics, no catalyst 480 23870 49.7 C Dibutyltin Oxide 12000 28080 2.3 D Cobalt (II) Acetate Tetrahydrate 11850 27510 2.3 E Antimony (III) Oxide 9950 23100 2.3 F Manganese (II) Acetate Tetrahydrate 7540 24590 3.3 G Titanium (IV) Butoxide 3800 25680 6.8 H Zinc Acetate Dihydrate 3600 24780 6.9 I Dibutyltin Dilaurate 3580 27820 7.8

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• 1995
  • 1995-05-22 US US08/447,333 patent/US5605979A/en not_active Expired - Fee Related
• 1996
  • 1996-03-26 CA CA002172679A patent/CA2172679A1/en not_active Abandoned
  • 1996-05-09 EP EP96107335A patent/EP0744430A3/de not_active Withdrawn
  • 1996-05-20 JP JP8148696A patent/JPH08311189A/ja active Pending
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